The present disclosure relates to an image forming apparatus including a seal member sealing toner scattered from a developing device.
An electro-photographic image forming apparatus is provided with a rotatable photosensitive drum, and a developing device and a transferring unit disposed in the order along a rotating direction of the photosensitive drum. As the photosensitive drum rotates, a toner image is formed on the photosensitive drum by the developing device and is transferred by the transferring unit from the photosensitive drum onto a recording medium such as an intermediate transferring belt.
In such image forming apparatus, there is a case where toner scattered from the developing device goes around into a space on a downstream side in the rotating direction of the photosensitive drum beyond the transferring unit from both side end portions in a rotating shaft direction of the photosensitive drum. In a case where a static eliminator removing residual electric charge of the photosensitive drum is provided on the downstream side in the rotating direction beyond the transferring unit, if the toner gone around into the space adheres both end portions of the static eliminator in the rotating shaft direction, a quantity of eliminating light is reduced, causing a problem that an eliminating effect degrades.
Then, there is a case where a seal member made of elastic member such as foaming urethane is used to prevent the scattered toner from leaking out of the both end portions of the photosensitive drum in the rotating shaft direction.
As shown in FIG. 7A, the seal member 100 has a two-layered structure of a slide member 101 and an elastic member 102. The slide member 101 is configured to come in contact with toner image non-forming areas on the both end portions of the photosensitive drum 110 in the rotating shaft direction. The elastic member 102 is configured to press the slide member 101 against the toner image non-forming area. The two-layered structure makes it possible to reduce a damage on the intermediate transferring belt because side edges of the intermediate transferring belt abuts with the elastic members 102 when the intermediate transferring belt meanders.
However, when the seal member 100 as described above is used, there is a case where a friction between the toner image non-forming area and the slide member 101 increases depending on surface property of the toner image non-forming area of the photosensitive drum 110, and the slide member 101 may be pulled in the rotating direction of the photosensitive drum 110. Then, as shown in FIG. 7B, the elastic member 102 is pulled by the slide member 101 and comes into contact with the surface of the photosensitive drum 110, causing a problem in which abnormal noise is generated.